Tools to keep aboard a twin-diesel trawler

Most trawler tool lists say “a good socket set” and stop there. We wanted to know exactly what our boat needs, so we went through 60 manuals for the equipment aboard, including the original DeFever owner’s manual, and added what other owners of the same machinery report needing. This is the result. It’s built around our boat, but most of it applies to any older twin-diesel trawler.

Our machinery: twin Caterpillar 3208 TA diesels, a 12 kW and a 20 kW Northern Lights generator, Naiad stabilizers, Hynautic hydraulic steering, a Wesmar DC bow thruster, a Maxwell windlass, a Sea Recovery watermaker and chilled-water air conditioning.

Start with this: you need SAE and metric

An older Taiwan-built trawler is a mix. Our Caterpillar engines, steering, watermaker, air conditioning, strainers and fuel filters are SAE. The Northern Lights generators (Shibaura blocks) and the Maxwell windlass are metric. Hull hardware is a mix of both. Buy every core tool in both systems.

The core kit

• Sockets: 1/4”, 3/8” and 1/2” drive, SAE and metric, deep and shallow. A 3/4” drive breaker bar and large sockets for stabilizer fin bolts and prop nuts.
• Wrenches: a full combination set in both systems, plus flare-nut wrenches. Include a 3/4” open-end for the 3208 injector line nuts; you’ll need it to bleed the fuel system.
• Two torque wrenches: one in inch-pounds (to about 200) and one in foot-pounds (to about 250). The 3208 injector nuts are 30 ± 5 foot-pounds. Stabilizer and steering fittings have their own values; keep them written down near the wrenches.
• Hex keys: long-arm sets in both systems, for cutless bearing set screws and stabilizer cap screws.
• Hose clamp drivers: 1/4” and 5/16” nut drivers. You’ll use them more than anything else on the list.
• Pliers and grips: standard pliers, Vise-Grips and snap-ring pliers.
• Filter tools: strap and chain wrenches, and filter wrenches sized for both the engine and generator filters.
• An impeller puller. Raw-water impellers fail often, and a puller turns a frustrating job into a ten-minute one.
• Feeler gauges in both systems, for valve lash and shaft alignment.
• A grease gun for the windlass and stabilizer trunnions.
• Inspection tools: a borescope, an infrared thermometer, a mechanic’s stethoscope, an inspection mirror and good headlamps.
• Power tools: a cordless drill and a Dremel. Our windlass manual says not to use power tools on it, so we won’t.

Electrical test gear

• A digital multimeter with a 50-foot lead. The factory bonding check runs from a transom zinc to every through-hull, strut and rudder, and that takes reach.
• A clamp-on AC/DC ammeter. We’ll use it on shore power, the generators, the air conditioning, the inverters and the thruster. It’s also how we’ll confirm the loads for our 48-volt power system.
• A battery load tester. Our sealed batteries call for a load tester and voltmeter, not a hydrometer.
• Crimping: a ratcheting crimper for small wire, adhesive heat-shrink and a heat gun, plus a hydraulic or hammer crimper and a cable cutter for 2/0 to 4/0 battery cable.
• A non-contact voltage tester and an outlet polarity tester.

Tools for specific systems

Caterpillar 3208 engines. The Cat engine turning tool (9S-9082) for setting valve lash. Sockets for the cooling-system zincs. A descaling rig: a bucket, a transfer pump, hoses and descaler. A coolant tester and test strips for the supplemental coolant additive. An oil-sample pump, so we can send oil for analysis at every change.

Generators. A filter wrench (the new filter goes on hand-tight), small metric wrenches for the bleed screws, and the factory spares kit for each model: impellers, filters, a belt and a thermostat.

Fuel. Spare elements for every Racor filter, the T-handle and bowl wrench, a 5-gallon jug and plenty of absorbent pads.

Running gear. A packing extractor and two wrenches sized to the stuffing box nuts. Lubricant-impregnated flax packing; our factory manual warns against graphite packing because it creates a galvanic cell. A prop puller. One detail worth knowing: on our boat, the right-hand shaft has left-hand-thread prop nuts.

Hydraulic steering. A hand air pump with a gauge that reads past 100 psi, to keep the reservoir at its specified pressure. Bleeding it takes two people.

Stabilizers. A grease gun for the trunnions. A nitrogen pre-charge check every six months, which we’ll hire out.

Air conditioning and watermaker. The descaling rig again, glycol for top-ups, a TDS meter for the watermaker, pickling and cleaning chemicals, and the pump oil. Refrigerant work requires an EPA-certified technician, so we won’t touch it. Owners of similar systems recommend carrying a spare chilled-water circulation pump and a spare seawater pump, and we plan to.

Heads. A full spares kit for our Galley Maid heads: seal sets, pump parts, a cutter blade, a solenoid and a timer.

The spares the factory told owners to carry

The 1986 DeFever owner’s manual is direct about it: carry spare impellers for each engine and generator, “since failure of the rubber impellers is common,” and carry spare alternator and water pump belts. Forty years later, that’s still the first line on our spares list.

What we’ll borrow or hire

Some tools cost more than they’re worth to own on a boat: an ultrasonic thickness gauge, a shop press, a nitrogen charging kit, a stabilizer fin puller and refrigerant gauges. We’ll hire those, or the technician will bring them.

What we still need to learn

We haven’t yet measured the stuffing box nut size, confirmed the hydraulic steering fluid or written the tool list for the transmissions. We’ll update this guide once we’re aboard and have more detail.